The present invention relates to a coupling construction for coupling press rolls forming a nip in which a large linear load exists, particularly an extended-nip, and a method for joining together a pair of rolls in a nip in which a large linear load exists, especially an extended-nip.
A press nip formed between a pair of extended-nip rolls typically consists of a pair of rolls such as SYM-ZL and SYM-BELT rolls. A special feature of an extended-nip is the high linear load applied therein to dewater the web. The maximum linear load is generally of an order of about 1200 kN/m. For such a relatively high linear load, a conventional screw coupling arrangement for the rolls is not possible, because, in order to overcome the linear load, roughly 130 screws per roll would be needed. This would be uneconomical in practice.